Hilbert-Speiser number fields and Stickelberger ideals
Let be a prime number. We say that a number field satisfies the condition when any abelian extension of exponent dividing has a normal integral basis with respect to the ring of -integers. We also say that satisfies when it satisfies for all . It is known that the rationals satisfy for all prime numbers . In this paper, we give a simple condition for a number field to satisfy in terms of the ideal class group of and a “Stickelberger ideal” associated to the Galois group...